U.S. patent application number 16/081981 was filed with the patent office on 2019-03-28 for well treatment methods.
The applicant listed for this patent is SCHLUMBERGER TECHNOLOGY CORPORATION. Invention is credited to Avinash RAMESH.
Application Number | 20190093006 16/081981 |
Document ID | / |
Family ID | 59743294 |
Filed Date | 2019-03-28 |
United States Patent
Application |
20190093006 |
Kind Code |
A1 |
RAMESH; Avinash |
March 28, 2019 |
WELL TREATMENT METHODS
Abstract
Methods include delivering a well treatment fluid comprising
wellsite material contained within a water soluble degradable
package, mixing the well treatment fluid, and pumping the mixed
well treatment fluid downhole.
Inventors: |
RAMESH; Avinash; (Houston,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SCHLUMBERGER TECHNOLOGY CORPORATION |
Sugar Land |
TX |
US |
|
|
Family ID: |
59743294 |
Appl. No.: |
16/081981 |
Filed: |
March 1, 2017 |
PCT Filed: |
March 1, 2017 |
PCT NO: |
PCT/US2017/020069 |
371 Date: |
September 4, 2018 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
62301949 |
Mar 1, 2016 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C09K 8/68 20130101; C09K
8/70 20130101; C09K 8/035 20130101; C09K 2208/08 20130101 |
International
Class: |
C09K 8/70 20060101
C09K008/70; C09K 8/035 20060101 C09K008/035 |
Claims
1. A method comprising: delivering a well treatment fluid
comprising wellsite material contained within a water soluble
degradable package; mixing the well treatment fluid; and pumping
the mixed well treatment fluid downhole.
2. The method of claim 1 wherein the degradable package comprises
at least one wellsite material.
3. The method of claim 2 wherein the at least one wellsite material
is a fiber.
4. The method of claim 1 wherein the degradable package comprises a
polyvinyl alcohol internal layer and a cellulosic outer layer.
5. A method of delivering fibers into a well treatment fluid, the
method comprising: providing an aqueous based treatment fluid;
adding a degradable package containing the fibers into the
treatment fluid; and mixing the treatment fluid.
6. The method of claim 5 wherein the degradable package comprises
at least one wellsite material.
7. The method of claim 5 wherein the at least one wellsite material
is a fiber.
8. The method of claim 5 wherein the degradable package comprises a
polyvinyl alcohol internal layer and a cellulosic outer layer.
Description
BACKGROUND
[0001] The present application claims priority to Provisional
Application Ser. No. 62/301949 filed on Mar. 1, 2016, which is
incorporated herein by reference in its entirety.
[0002] Drilling, cementing, stimulation, and various treatments,
including workover operations, of oil and gas wells frequently
require using various chemical additives.
[0003] Various fluids may be delivered to the wellsite to perform
wellsite operations. For example, during drilling, drilling fluids
(e.g., muds) may be pumped into the wellbore to facilitate drilling
and/or to line the wellbore. In another example, during production,
treatment/stimulation fluid may be injected into the formation to
fracture the formations. Such injected treatment/stimulation fluid
may include, for example, acids to enhance the fractures, proppants
to prop open the fractures, and the like. Various techniques known
in the art may be used to deliver the treatment/stimulation fluid
to the wellsite.
[0004] Chemical additives may be delivered in a variety of shapes
such as particles, rod, blobs, flocs, and have various aspects
ratios. For example, the use of high aspect ratio particles has
been recognized as being beneficial in a multitude of applications
such as proppant transport, loss circulation, fluid loss, diversion
and others.
[0005] Delivery of the chemical additives has been a challenge in
the industry for many years since the nature, shape, density, or
characteristics of the chemical additives may create issues in
transporting such additives to the wellsite, delivering them
through wellsite equipment, or for mixing them in the desired
treatment fluid.
SUMMARY
[0006] In embodiments, methods disclosed herein include delivering
a well treatment fluid comprising wellsite material contained
within a water soluble degradable package, mixing the well
treatment fluid, and pumping the mixed well treatment fluid
downhole.
[0007] In other embodiments, methods of delivering fibers into a
well treatment fluid disclosed herein include providing an aqueous
based treatment fluid, adding a degradable package containing the
fibers into the treatment fluid, and mixing the treatment
fluid.
DETAILED DESCRIPTION
[0008] The description and examples are presented solely for the
purpose of illustrating some embodiments and should not be
construed as a limitation to the scope and applicability. Although
some of the following discussion emphasizes diversion in
fracturing, the destructible container and method may be used in
many other wellbore operations. Some embodiments shall be described
in terms of treatment of horizontal wells, but are equally
applicable to wells of any orientation. Some embodiments shall be
described for hydrocarbon production wells, but it is to be
understood that they may be used for wells for production of other
fluids, such as water or carbon dioxide, or, for example, for
injection or storage wells. It should also be understood that
throughout this specification, when a concentration or amount range
is described as being useful, or suitable, or the like, it is
intended that any and every concentration or amount within the
range, including the end points, is to be considered as having been
stated. Furthermore, each numerical value should be read once as
modified by the term "about" (unless already expressly so modified)
and then read again as not to be so modified unless otherwise
stated in context. For example, "a range of from 1 to 10" is to be
read as indicating each and every possible number along the
continuum between about 1 and about 10. In other words, when a
certain range is expressed, even if only a few specific data points
are explicitly identified or referred to within the range, or even
when no data points are referred to within the range, it is to be
understood that the inventors appreciate and understand that any
and all data points within the range are to be considered to have
been specified, and that the inventors have possession of the
entire range and all points within the range.
[0009] The present disclosure relates to water soluble degradable
packages to deliver wellsite materials, such as chemical materials
into wellbore treatment fluid and methods of using said packages.
The disclosure comprises introducing the water soluble degradable
packages containing chemicals or materials into the pumping
line.
[0010] "Wellsite materials" as used herein may refer to wellsite
fluids, wellbore fluids, and/or solids, such as chemicals,
proppants, fibers, slurries and/or drilling muds. By way of
example, the wellsite materials may include solid proppant added to
fracturing fluid, solid and/or liquid chemical additives added to
fracturing slurry (e.g., fibers, particulates, crosslinkers,
breakers, corrosion inhibitors), fibers and particulates (and other
lost circulation materials) added to treatment pills (preventative
or remedial), solid hydrofluoric (HF) acid precursor added to acid
solution (e.g., hydrofluoric, NH4HF2) for sandstone acidizing,
solid cement additives added during cementing operations, and/or
other solid and/or liquid wellsite components.
[0011] "Degradable packages" may refer to discrete packages of
wellsite materials. The wellsite packages may include specified
solid and/or liquid components packaged in specified amounts into
packaging, such as containers, coatings, plastics, shrink wrap,
and/or the like, that are degradable. The packaging may be used to
prevent exposure of the wellsite materials to air or other
potentially detrimental materials. The packaging may also include
components that act as part of the materials used in treatment, and
optionally may be reusable. The wellsite packets may be individual
packets, a long tubular packet or multiple individual packets
joined together in chains or sheets. The wellsite packets may be
mixed with fluid(s) to form "wellsite mixtures." Examples of
wellsite mixtures may include: stimulation fluid, such as acid;
fracturing fluid for hydraulic fracturing, such as proppant laden
fluid (gas or liquid, e.g., water), and various additives; drilling
mud; cement slurry; treatment fluid, such as surface water
treatment; or other wellsite fluids that may or may not include
particle(s), fiber(s) or other solids.
[0012] "Degradable" may include water-soluble. The packages
dissolve in the aqueous treatment fluid thus releasing the wellsite
material it contained.
[0013] Suitable methods for delivering the degradable packages are
disclosed for example in US 2015-0075796 incorporated herein by
reference in its entirety.
[0014] Using the disclosed degradable packages enable a precise
metering of the quantity of wellsite materials to be included into
the treatment fluid and also avoid issues that were sometimes
difficult to overcome such as dust for low density materials or
clumping or metering challenges for high aspect ratios
materials.
[0015] The packages disclosed herein may be water soluble at
ambient temperature. Potential compositions contemplated include
packages formed from polyvinyl alcohol and cellulose. Such
combination present several advantages such as storage. Indeed,
known water soluble films or packages are always challenging to
store or transport since the ambient moisture used to provoke early
deterioration thus necessitating various prevention means such as
using a desiccant or detackifier. The presently disclosed packages
may solve these issues.
[0016] In embodiments, and to facilitate handling and make more
flexible the concentrations achievable by adding the present
packages into the treatment fluids, shapes contemplated include
squares of 3 inches by 3 inches with a width of about 0.5 to about
1 inch. This allow to include very precise quantity of wellsite
material in the treatment fluid; for example when polylactides
fibers are included into the degradable packages, one package would
contain about 35 g of fibers.
[0017] Once a person skilled in the art has determined the amount
of wellsite material to be included in the treatment fluid, the
corresponding amount of pouches can be added to the fluid and will
readily dissolve on surface thus enabling the mixing and pumping of
an appropriate treatment fluid from surface.
[0018] When fiber is the main wellsite material, using particle or
fiber-holding degradable packages significantly simplifies wellsite
delivery. Problems with existing methods of fiber and/or particle
delivery based on using screw feeders include, but are not limited
to, metering difficulties and plugging of equipment. Wellsite
delivery of special materials, such as fibers and/or particles, in
degradable packages solves these problems, because such packages
may be introduced into the treating fluid with the same techniques
as commonly used for proppant or any solid or particulate material.
In embodiment fibers and/or particulates are vacuum packed into
small bundles (to maximize the concentration) and surrounded by a
coating or put into an enclosure, for example shrink-wrapped or
vacuum packed.
[0019] As mentioned earlier, the degradable packages are soluble in
the treatment fluids. Said fluids may be slickwater, flowed back
water, brine, viscosified fluids or even crosslinked fluids.
[0020] The wellsite materials to be included in the degradable
packages may be of any compatible nature, i.e., non degrading the
internal layer of the degradable packages.
[0021] Nonlimiting examples of wellsite materials that may be
contained include certain polymer materials that are capable of
generating acids upon degradation. These polymer materials may
herein be referred to as "polymeric acid precursors"; they can be
used as destructible shell materials or as degradable diverting
materials, depending on their properties. These materials are
typically solids at room temperature. The polymeric acid precursor
materials include the polymers and oligomers that hydrolyze or
degrade in certain chemical environments under known and
controllable conditions of temperature, time and pH to release
organic acid molecules that may be referred to as "monomeric
organic acids." As used herein, the expression "monomeric organic
acid" or "monomeric acid" may also include dimeric acid or acid
with a small number of linked monomer units that function similarly
to monomer acids composed of only one monomer unit, in that they
are fully in solution at room temperature.
[0022] Polymer materials may include those polyesters obtained by
polymerization of hydroxycarboxylic acids, such as the aliphatic
polyesters of lactic acid, referred to as polylactic acid; of
glycolic acid, referred to as polyglycolic acid; of 3-hydroxbutyric
acid, referred to as polyhydroxybutyrate; of 2-hydroxyvaleric acid,
referred to as polyhydroxyvalerate; of epsilon caprolactone,
referred to as polyepsilon caprolactone or polycaprolactone; the
polyesters obtained by esterification of hydroxyl aminoacids such
as serine, threonine and tyrosine; and the copolymers obtained by
mixtures of the monomers listed above. A general structure for the
above-described homopolyesters is:
H-{O-[C(R1,R2)].sub.x-[C(R3,R4)].sub.y-C.dbd.O}.sub.z--OH [0023]
where R1, R2, R3, and R4 are either H, linear alkyl, such as
CH.sub.3, CH.sub.2CH.sub.3 (CH.sub.2).sub.nCH.sub.3, branched
alkyl, aryl, alkylaryl, a functional alkyl group (bearing
carboxylic acid groups, amino groups, hydroxyl groups, thiol
groups, or others) or a functional aryl group (bearing carboxylic
acid groups, amino groups, hydroxyl groups, thiol groups, or
others); [0024] x is an integer between 1 and 11; [0025] y is an
integer between 0 and 10; and [0026] z is an integer between 2 and
50,000.
[0027] Under appropriate conditions (pH, temperature, water
content) polyesters such as those described here may hydrolyze and
degrade to yield hydroxycarboxylic acids and compounds such as
those acids referred to in the foregoing as "monomeric acids."
[0028] One example of a suitable degradable polymeric acid
precursor, as mentioned above, is a polyester, such as the polymer
of lactic acid, sometimes called polylactic acid, "PLA,"
polylactate or polylactide. Lactic acid is a chiral molecule and
has two optical isomers. These are D-lactic acid and L-lactic acid.
The poly(L-lactic acid) and poly(D-lactic acid) forms are generally
crystalline in nature. Polymerization of a mixture of the L- and
D-lactic acids to poly(DL-lactic acid) results in a polymer that is
more amorphous in nature. The polymers described herein are
essentially linear. The degree of polymerization of the linear
polylactic acid can vary from as few units as necessary to make
them solids under downhole conditions to several thousand units
(e.g. 2000-5000). Cyclic structures may also be used. The degree of
polymerization of these cyclic structures may be smaller than that
of the linear polymers. These cyclic structures may include cyclic
dimmers if they are solids under storage and wellsite ambient
conditions.
[0029] Another example is the polymer of glycolic acid
(hydroxyacetic acid), also known as polyglycolic acid ("PGA"), or
polyglycolide. Other materials suitable as polymeric acid
precursors (destructible shell materials or degradable diverting
materials, depending on their properties) are all those polymers of
glycolic acid with itself or with other hydroxy-acid-containing
moieties, for example as described in U.S. Pat. Nos. 4,848,467;
4,957,165; and 4,986,355. Further examples of potential material
may be found in US 2012-0285695 incorporated herein by reference in
its entirety.
[0030] The thickness of the container shell may range from about 50
microns to about 100 microns, or it may be from 60 microns to 80
microns. Optionally, the container may be made with several layers,
for example up to about 10 layers, that may be the same or
different. In embodiments the internal layer may be made of
polyvinyl alcohol film and the outer layer may be made of cellulose
film. Additional films may also be used in between for example to
tailor the dissolution rate in the aqueous fluid.
[0031] A process of preparing water-soluble containers is disclosed
in U.S. Pat. No. 6,898,921. The process comprises a) thermoforming
a first poly(vinyl alcohol) film having a water content of less
than 5% to produce a pocket; b) filling the pocket with a
composition; c) placing a second film on the top of the pocket; and
d) sealing the first film and the second film together. The process
may be adapted for use in some embodiments.
[0032] While the invention has been shown in only some of its
forms, it should be apparent to those skilled in the art that it is
not so limited, but is susceptible to various changes and
modifications without departing from the scope of the
invention.
[0033] Accordingly, it is appropriate that the appended claims be
construed broadly and in a manner consistent with the scope of the
invention.
* * * * *